Two businessmen associated with Rudy Giuliani may end up facing additional charges.

Lev Parnas and Igor Fruman have already pleaded not guilty to criminal campaign finance charges. Federal prosecutors say they were involved in a conspiracy to funnel foreign money into U.S. elections.

An assistant U.S. attorney told a New York judge Monday that the two defendants are "under investigation for additional crimes." The prosecutor didn't give details about those other crimes, but he did say the Justice Department is "likely" to file new charges against Parnas and Fruman.